US3760292A - Integrated feedback laser - Google Patents
Integrated feedback laser Download PDFInfo
- Publication number
- US3760292A US3760292A US00128165A US3760292DA US3760292A US 3760292 A US3760292 A US 3760292A US 00128165 A US00128165 A US 00128165A US 3760292D A US3760292D A US 3760292DA US 3760292 A US3760292 A US 3760292A
- Authority
- US
- United States
- Prior art keywords
- medium
- optical frequency
- perturbations
- frequency oscillator
- optical
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Lifetime
Links
- 230000010355 oscillation Effects 0.000 claims abstract description 31
- 230000003287 optical effect Effects 0.000 claims description 47
- 230000000737 periodic effect Effects 0.000 claims description 30
- 238000005086 pumping Methods 0.000 claims description 22
- 230000008713 feedback mechanism Effects 0.000 claims description 13
- 230000005540 biological transmission Effects 0.000 claims description 6
- 239000011343 solid material Substances 0.000 claims description 2
- 239000011149 active material Substances 0.000 abstract description 3
- 108010010803 Gelatin Proteins 0.000 description 6
- 229920000159 gelatin Polymers 0.000 description 6
- 239000008273 gelatin Substances 0.000 description 6
- 235000019322 gelatine Nutrition 0.000 description 6
- 235000011852 gelatine desserts Nutrition 0.000 description 6
- 230000003595 spectral effect Effects 0.000 description 6
- 239000000758 substrate Substances 0.000 description 6
- 230000001427 coherent effect Effects 0.000 description 5
- 239000000975 dye Substances 0.000 description 5
- 239000011521 glass Substances 0.000 description 4
- 239000007787 solid Substances 0.000 description 4
- OKKJLVBELUTLKV-UHFFFAOYSA-N Methanol Chemical compound OC OKKJLVBELUTLKV-UHFFFAOYSA-N 0.000 description 3
- 230000007246 mechanism Effects 0.000 description 3
- 239000004065 semiconductor Substances 0.000 description 3
- 239000010409 thin film Substances 0.000 description 3
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 2
- 229910052779 Neodymium Inorganic materials 0.000 description 2
- VYXSBFYARXAAKO-WTKGSRSZSA-N chembl402140 Chemical compound Cl.C1=2C=C(C)C(NCC)=CC=2OC2=C\C(=N/CC)C(C)=CC2=C1C1=CC=CC=C1C(=O)OCC VYXSBFYARXAAKO-WTKGSRSZSA-N 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 239000010408 film Substances 0.000 description 2
- -1 krypton ion Chemical class 0.000 description 2
- GQYHUHYESMUTHG-UHFFFAOYSA-N lithium niobate Chemical compound [Li+].[O-][Nb](=O)=O GQYHUHYESMUTHG-UHFFFAOYSA-N 0.000 description 2
- 239000000463 material Substances 0.000 description 2
- QEFYFXOXNSNQGX-UHFFFAOYSA-N neodymium atom Chemical compound [Nd] QEFYFXOXNSNQGX-UHFFFAOYSA-N 0.000 description 2
- 230000005855 radiation Effects 0.000 description 2
- 239000002904 solvent Substances 0.000 description 2
- 238000001228 spectrum Methods 0.000 description 2
- 101000703464 Homo sapiens SH3 and multiple ankyrin repeat domains protein 2 Proteins 0.000 description 1
- 208000025814 Inflammatory myopathy with abundant macrophages Diseases 0.000 description 1
- 102100030680 SH3 and multiple ankyrin repeat domains protein 2 Human genes 0.000 description 1
- XKRFYHLGVUSROY-UHFFFAOYSA-N argon Substances [Ar] XKRFYHLGVUSROY-UHFFFAOYSA-N 0.000 description 1
- 229910052786 argon Inorganic materials 0.000 description 1
- 239000000470 constituent Substances 0.000 description 1
- 230000008030 elimination Effects 0.000 description 1
- 238000003379 elimination reaction Methods 0.000 description 1
- 238000001914 filtration Methods 0.000 description 1
- 108010025899 gelatin film Proteins 0.000 description 1
- 229910052743 krypton Inorganic materials 0.000 description 1
- 239000000990 laser dye Substances 0.000 description 1
- 230000009021 linear effect Effects 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 238000000034 method Methods 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
- 229910052757 nitrogen Inorganic materials 0.000 description 1
- 230000009022 nonlinear effect Effects 0.000 description 1
- 230000003534 oscillatory effect Effects 0.000 description 1
- WVDDGKGOMKODPV-ZQBYOMGUSA-N phenyl(114C)methanol Chemical compound O[14CH2]C1=CC=CC=C1 WVDDGKGOMKODPV-ZQBYOMGUSA-N 0.000 description 1
Images
Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01S—DEVICES USING THE PROCESS OF LIGHT AMPLIFICATION BY STIMULATED EMISSION OF RADIATION [LASER] TO AMPLIFY OR GENERATE LIGHT; DEVICES USING STIMULATED EMISSION OF ELECTROMAGNETIC RADIATION IN WAVE RANGES OTHER THAN OPTICAL
- H01S3/00—Lasers, i.e. devices using stimulated emission of electromagnetic radiation in the infrared, visible or ultraviolet wave range
- H01S3/09—Processes or apparatus for excitation, e.g. pumping
- H01S3/091—Processes or apparatus for excitation, e.g. pumping using optical pumping
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B82—NANOTECHNOLOGY
- B82Y—SPECIFIC USES OR APPLICATIONS OF NANOSTRUCTURES; MEASUREMENT OR ANALYSIS OF NANOSTRUCTURES; MANUFACTURE OR TREATMENT OF NANOSTRUCTURES
- B82Y20/00—Nanooptics, e.g. quantum optics or photonic crystals
-
- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
- G02B6/10—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings of the optical waveguide type
- G02B6/12—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings of the optical waveguide type of the integrated circuit kind
- G02B6/122—Basic optical elements, e.g. light-guiding paths
- G02B6/124—Geodesic lenses or integrated gratings
-
- G—PHYSICS
- G02—OPTICS
- G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
- G02F1/00—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
- G02F1/35—Non-linear optics
- G02F1/39—Non-linear optics for parametric generation or amplification of light, infrared or ultraviolet waves
Definitions
- FIG. 3 Sheets-Sheet 2 FIG. 3 32 as 1ST CDHERENT 2ND COHERENT PUMP PUMP INTERFERENCE PUMPING PATTERN OUTPUT I UTILIZATION I I APPARATUs soLID STATE A LAsER MEDIUM FIG. 4
- This invention relates to laser devices and, more particularly, to feedback arrangements for laser oscillators.
- Laser oscillators in general, consist of an active medium which produces gain and a resonator structure which provides feedback to produce the desired buildup of oscillations.
- the resonator structure may be any of a number of forms. The most common is, perhaps, a pair of mirrors, one at each end of the active medium, which reflect the optical energy back into the active medium.
- the mirrors may be planar or, as is more often the case, concave, in 'which case a focusing effect is realized.
- the alignment of the mirrors and their spacing is to some extent critical.
- the mechanical problem of maintaining alignment and spacing under operating conditions gives rise to complex and expensive arrangements. It is also usually desirable that the mirrors present little loss to the impinging light beam.
- low loss mirrors such as dielectric mirrors, are not only expensive, but generally are delicate and easily damaged.
- the resonator can be formed by silvering the ends of the solid active medium.
- these ends must be extremely flat and parallel or, in the case of curved mirrors, must be carefully ground to the proper radii and smoothness.
- the present invention overcomes the aforementioned problems through the elimination of the resonator cavity as such.
- the feedback mechanism essential to oscillation, is distributed through and integrated with the active medium of the laser.
- the feedback structure is created by substantially time constant, spatially periodic perturbations in the transmission characteristics of the medium along the length thereof which may take the form of variations in the gain, index of refraction, propagation constant or other parameter of the medium.
- Such a distributed, integral feedback arrangement is inherently mechanically stable and in addition, because of the grating-like nature of the feedback structure, a filtering action occurs which drastically narrows the spectral bandwidth relative to conventional feedback arrangements.
- the laser active medium comprises a film of dichromated gelatin deposited on a glass substrate and impregnated with a dye having laser capability.
- An interference pattern exists in the gelatin layer, having been formed by holographic means, thereby creating within the medium a time constant spatial modulation of the refractive index ofthe active medium.
- the laser oscillates in an extremely narrow spectral band.
- substantially time constant, spatially periodic perturbatins in the transmission characteristics of the laser are produced by periodic gain variations, periodic loading of the medium, or periodic deformations, all in a variety of active media.
- All of the illustrative embodiments of the invention have in common the principal feature of a substantially time constant, spatial periodicity in the transmission characteristics of the active medium.
- FIG. 1 is a diagrammatic illustration of the principles of the present invention
- FIG. 2 is an illustrative embodiment of the invention in which refractive index is varied
- FIGS. 3, 4 and 5 are illustrative embodiments of the invention in which the gain mechanism is varied
- FIGS. 6 and 7 are illustrative embodiments of the in vention in which the propagation constant is varied.
- FIG. 8 illustrates the principles of the invention as applied to a parametric oscillator.
- FIG. I there is shown diagrammatically a distributed feedback laser structure 11 and a suitable pumping means 12.
- the structure I1 has a periodic spatial variation of period A, which may take one of a number of forms, such as a variation in the index of refraction n of the medium or a variation in the gain constant at. These variations can be expressed by n(z) n n cos Kz i and where z is measured along the optic axis, K 21r/A, and n and 01, are the amplitudes of the spatial modulation of period A.
- Such a structure when the active medium is excited above a threshold level by the pump source 12, oscillates in the vicinity of a wavelength A, given by which defines two counter-running waves of complex amplitudes R and S. As shown in the graph of FIG. ll, these waves grow in the presence of gain and feed energy to each other.
- the boundary conditions for the wave amplitudes are given by where L is the length of the laser structure.
- L is the length of the laser structure.
- a wave starts at zero amplitude and grows to a maximum at the other end.
- Each pair of periodic variations can be viewed as forming a resonator of length A in which the end surfaces are partially transmitting and partially reflecting.
- FIG. I can be viewed as a plurality of partial resonators in tandem.
- FIG. 2 depicts an illustrative embodiment of the invention wherein the laser member comprises a dichromated gelatin film 21 deposited on, for example, a glass substrate 22. Formed within the film 21 are a plurality of interference planes 23 of index of refraction change, spaced a distance A apart.
- the planes 23 may be produced in the gelatin by interference between two coherent ultraviolet beams from, for example, a I-Ie-Cd laser, after which the gelatin is developed. This is a holographic technique well known to workers in the art, and produces time constant spatially periodic index of refraction changes in the gelatin.
- the gelatin is impregnated with an active laser medium such as a laser dye, e.g., Rhodamine 6G.
- Suitable pumping means such as, for example, the ultraviolet radiation from a nitrogen laser, serves to activate the laser.
- a laser of a length of 10mm and a width of 0.1 mm, with a frine spacing A of 03pm pumping densities in excess of 10 W/cm produce laser oscillations in the structure at approximately 0.63am with a spatial bandwidth of less than0.5A.
- a similar laser, without the periodic variations of refractive index of the embodiment of FIG. 2 produces oscillations centered at approximately 0.59pm and having a bandwidth of approximately 50A.
- the present invention as embodied in the device of FIG. 2, produces line narrowing by a factor of 100.
- FIG. 3 there is shown still another embodiment of the present invention wherein a solid state laser medium 31 such as, for example, neodymium YAG, has induced therein a substantially time constant, spatially periodic interference pattern produced by the interference between angularly directed pumping lights from first and second coherent pump sources 32 and 33, thereby producing periodic gain variation.
- the two pump sources shown are intended to be symbolic or numerous arrangements.
- An expeditious way of achieving the desired frequency and phase relationship of the two beams is through the use of a single pump whose output is split into two beams with a mirror arrangement for directing the beams into the median at the desired angles. Proper choice of pump wavelength and angular direction of the beams produces the desired spacing A.
- the output of the laser may be utilized in any suitable manner such as, for example, utilization apparatus 34.
- the arrangement of FIG. 3 has the added virtue of tunability since variations in the angle 0 produce changes in A, thereby changing the laser wavelength.
- the wavelength of oscillation A is a function of the index of refraction n of the medium.
- tuning may also be achieved by varying n, where the nature of the medium permits.
- the index of refraction can easily be varied from 1.33 to 1.55 by varying the proportions of the solvent constituents.
- a change of 0.01 in n changes A, by approximately 43A. for a dye concentration of I X 10*M.
- Periodic pump variations similar to those of FIG. 3 can also be realized by the arrangement of FIG. 4 wherein the laser medium 41, which may be any of a number of types, has deposited thereon or in proximity thereto an optical grating 42 which produces within the medium periodic intensity variations in the pumping energy from the pump source 43.
- the laser medium 41 which may be any of a number of types, has deposited thereon or in proximity thereto an optical grating 42 which produces within the medium periodic intensity variations in the pumping energy from the pump source 43.
- FIG. 5 In a semiconductor laser, the pump periodicities of FIGS. 3 and 4 can be achieved by the arrangement of FIG. 5.
- the embodiment of FIG. 5 comprises a semiconductor laser 51 of suitable material deposited or mounted on a substrate 52.
- a current mask 53 On one surface of the member 51 is a current mask 53 which permits pumping or energizing current from a current supply electrode 54 to pass only through apertures 56 which are spaced a distance A apart. The net effect is to produce a periodic gain variation within the semiconductor laser member 51.
- the foregoing embodiments of the invention depend upon index of refraction or gain variations to achieve the desired results. It is also possible to produce a laser oscillator in accordance with the principles of the invention through spatially periodic variations of the propagation constant B of the active medium.
- FIG. 6 The device of FIG. 6 comprises a thin film active medium 61 of, for example, neodymium doped high index glass, mounted or deposited upon a suitable substrate 62. A source of pumping energy 63 serves to excite the active medium 6].
- Disposed on the surface of the medium 61 are a plurality of dielectric elements 64 of glass, for example, which extend across the member 61 and are parallel to each other. Elements 64 are spaced a distance A apart, and, through the mechanism of dielectric loading, producing variations in the propagations constant B of the thin film member 61, spaced a distance A apart.
- FIG. 7 there is shown an arrangement similar to that of FIG. 6.
- a thin film member 71 of suitable active material is mounted or deposited upon a suitable substrate 72.
- a pumping means 73 supplies energy to the medium 711.
- one surface of member 71 has a plurality of thickness variations 74 of periodicity A. These varia tions in turn produce variations in the propagation constant B of the medium, of a periodicity A.
- FIG. 8 there is shown an arrangement in which the principles of the invention are utilized in a parametric oscillator.
- a member 81 of suitable material such as, for example, lithium niobate
- a pumping laser 82 such as, for example, a krypton ion laser, which emits light in the red region of the spectrum.
- a time constant, spatially periodic index of refraction change by means of the interference between two coherent beams from auxiliary lasers 83 and 84, directed into the medium 81 at an angle 0 to each other.
- a pair of beam sources is intended to symbolize numerous arrangements.
- a single source with a beam splitter and scissor arrangement is perhaps the most expeditious way of insuring the proper phase and frequency relationships between the two beams.
- the interference pattern is created in the medium through the well known damage mechanism which occurs in lithium niobate, for example, when subjected to coherent radiation.
- the period A of the interference pattern may be such as to feed back the idler wave.
- the auxiliary laser or lasers 83, 84 may be argon ion lasers, which produce light in the ultraviolet region of the spectrum.
- A may be chosen to feed back the signal frequency, or, in certain cases, it may be such that both signal and idler are fed back.
- An optical frequency oscillator comprising an active medium and a feedback mechanism, said feedback mechanism comprising substantially time constant, spatially periodic perturbations in the transmission characteristics of the medium continuously along the length thereof and substantially transverse to the optical direction of propagation of energy in the medium, said perturbations being of sufficient magnitude and being spaced by an integral multiple of one-half wave lengths of the optical frequency oscillations to produce sufficient feedback of the optical energy to sustain oscillations, and means for exciting said active medium to produce oscillations.
- An optical frequency oscillator comprising an active medium and a feedback mechanism, said feedback mechanism comprising means for producing substantially time constant, spatially periodic perturbations in the gain characteristics of the medium continuously along the length thereof and substantially transverse to the direction of propagation of optical energy in the medium, said perturbations being of sufficient magnitude and being spaced by an integral multiple of onehalf wave lengths of the optical frequency oscillations to produce sufficient feedback of the optical energy to sustain oscillations, and pumping means for exciting said active medium to produce oscillations.
- An optical frequency oscillator as claimed in claim 5 wherein said means for producing substantially time constant, spatially periodic perturbations comprises means for directing pumping energy into said medium at an angle to the direction of pumping energy of said pumping means.
- An optical frequency oscillator as claimed in claim 5 wherein said means for producing substantially time constant, spatially periodic perturbations comprises means for causing the pump energy to enter said active medium at spaced intervals along the length thereof.
- An optical frequency oscillator comprising an active medium and a feedback mechanism, said feedback mechanism comprising means for producing substantially time constant, spatially periodic perturbations in the propagation constant of said medium continuously along the length thereof and substantially transverse to the direction of propagation of optical energy in the medium, said perturbations being of sufficient magnitude and being spaced by an integral multiple of onehalf wave lengths of the optical frequency oscillations to produce sufficient feedback of the optical energy to dium.
Abstract
Active materials having substantially time constant, spatially alternating variations in the propagation characteristics thereof produce laser oscillations when excited above a threshold of oscillation.
Description
nited States Patent Kogelnik et al.
[ 1 Sept. 18, 197.3
[54] INTEGRATED FEEDBACK LASER 3,239,688 3/1966 Price 307/312 3,579,142 1971 S 'l [75] Imam: PM 3 611 190 131971 K21? Jr.... Haven; Charles Vernon Shank, 3,451,010 6/1969 Maiman 331/945 Laurence, both of NJ.
[73] Assignee: Bell Telephone Laboratories, OTHER BLICATIONS Incorporated, Murray Hill, NJ. Miller: Integrated Opt1cs: An Introduction, The Bell [221 F1led= Mar-25, 1971 System Technical Journal, v01. 48, pp. 2059-2069, 211 App]. No.: 128,165 p 1969- Related US. Application Data [63] Continuation-impart of Ser. No. 100,659, Dec. 22, Primary Examiner-Edward Bauer 1970, abandoned. Attorney-W. L. Keefauver et al.
[52] US. Cl 331/94.5 C, 307/883, 330/4.3,
350/35 57 ABSTRACT [51] int. C1. H015 3/00 I v 1 [58] Field of Search 331/945; 330/43; Active materials having Substantially time constant,
307/883; 350/35 96 W6 spatially alternating variations in the propagation characteristics thereof produce laser oscillations when ex- [56] References C'ted cited above a threshold of oscillation.
UNITED STATES PATENTS 3,448,405 6/1969 Wolff 331/945 112 flCiaims, 8 Drawing Figures PUM P PUMP 23 RAYS Z] LASER L LASER OUTPUT OUTPUT Patented Sept. 18, 1973 3,760,292
3 Sheets-Sheet 1 TRANSMITTED WAVE REFLECTED WAVE v z o L/Q W-GAIN MEDIUM INPUT 3 5 WAVE I PERIODIC. +I P I L II TRANSMISSION T T A f I 1 t VARIAHONS PUMPING MEANS FIG. 2
PUMP 1 l l L PUMP 23 RAYS 2 LASER L LASER oUTPUT 'oUTPUT ///Y// A H.W. KOGELN/K uvvawrom C M SHANK Patented Sept. 18, 1973 3,760,292
3 Sheets-Sheet 2 FIG. 3 32 as 1ST CDHERENT 2ND COHERENT PUMP PUMP INTERFERENCE PUMPING PATTERN OUTPUT I UTILIZATION I I APPARATUs soLID STATE A LAsER MEDIUM FIG. 4
PUMP 4a 42 w 0 4| 1 I RESIDUAL PUMP A L LIGHT FIG. .5 54
CURRENT MASKS As IN CURRENT SUPPLY ELECTRODE STRIPE GEOMETRY 53 M A F 56 LAsER f ACTTVE MEDTUIVI SUBSTRATE OUTPUT 5| I Patented Sept. 18, 1973 3 Sheets-Sheet 5 FIG 7 PUMP OUTPUT FIG. 6
PUMPING MEANS IIIIIIIIIIIIII OuT PUT I AUXILLARY 2 AUXILLARY LASER LASER PUMPING LASER PERIODICITY IN REFRACTIVE INDEX VIA "DAMAGE"MECHAI\IISIVI SIGNAL WAVE OUTPUT OUTPUT INTEGRATED FEEDBACK LASER CROSS REFERENCE TO RELATED APPLICATION This application is a continuation-in-part of U.S. patent application of H. W. Kogelnik and C. V. Shank, Ser. No. 100,659, filed Dec. 22, 1970, now abandoned.
BACKGROUND OF THE INVENTION This invention relates to laser devices and, more particularly, to feedback arrangements for laser oscillators.
Laser oscillators, in general, consist of an active medium which produces gain and a resonator structure which provides feedback to produce the desired buildup of oscillations. The resonator structure may be any of a number of forms. The most common is, perhaps, a pair of mirrors, one at each end of the active medium, which reflect the optical energy back into the active medium. The mirrors may be planar or, as is more often the case, concave, in 'which case a focusing effect is realized. In virtually all cases the alignment of the mirrors and their spacing is to some extent critical. Furthermore, the mechanical problem of maintaining alignment and spacing under operating conditions gives rise to complex and expensive arrangements. It is also usually desirable that the mirrors present little loss to the impinging light beam. However, low loss mirrors, such as dielectric mirrors, are not only expensive, but generally are delicate and easily damaged.
In the case of solid state lasers, the resonator can be formed by silvering the ends of the solid active medium. However, these ends must be extremely flat and parallel or, in the case of curved mirrors, must be carefully ground to the proper radii and smoothness.
A further drawback to such resonator structures, as discussed in the foregoing, arises from the fact that the resonator is necessarily many wavelengths long. As a consequence, several oscillatory modes exist within the resonator, resulting in a broadening of the spectral band of the laser output.
In the prior art, some of the alignment problems can be obviated through the use of prisms, such as roof or corner prisms, to form the resonator reflecting surfaces. In some cases this also results in a fairly narrow spectral bandwidth. However, such prisms are quite difficult to manufacture to the desired degree of precision, and are, as a result, expensive.
SUMMARY OF THE INVENTION The present invention overcomes the aforementioned problems through the elimination of the resonator cavity as such. The feedback mechanism, essential to oscillation, is distributed through and integrated with the active medium of the laser. In particular, the feedback structure is created by substantially time constant, spatially periodic perturbations in the transmission characteristics of the medium along the length thereof which may take the form of variations in the gain, index of refraction, propagation constant or other parameter of the medium. Such a distributed, integral feedback arrangement is inherently mechanically stable and in addition, because of the grating-like nature of the feedback structure, a filtering action occurs which drastically narrows the spectral bandwidth relative to conventional feedback arrangements.
In an illustrative embodiment of the invention, the laser active medium comprises a film of dichromated gelatin deposited on a glass substrate and impregnated with a dye having laser capability. An interference pattern exists in the gelatin layer, having been formed by holographic means, thereby creating within the medium a time constant spatial modulation of the refractive index ofthe active medium. When pumped by suitable means in excess of the oscillation threshold, the laser oscillates in an extremely narrow spectral band.
In other embodiments of the invention, substantially time constant, spatially periodic perturbatins in the transmission characteristics of the laser are produced by periodic gain variations, periodic loading of the medium, or periodic deformations, all in a variety of active media.
All of the illustrative embodiments of the invention have in common the principal feature of a substantially time constant, spatial periodicity in the transmission characteristics of the active medium.
The various features and principles of the invention will be more readily apparent from the following detailed description read in conjunction with the accompanying drawings.
DESCRIPTION OF THE DRAWINGS FIG. 1 is a diagrammatic illustration of the principles of the present invention;
FIG. 2 is an illustrative embodiment of the invention in which refractive index is varied;
FIGS. 3, 4 and 5 are illustrative embodiments of the invention in which the gain mechanism is varied;
FIGS. 6 and 7 are illustrative embodiments of the in vention in which the propagation constant is varied; and
FIG. 8 illustrates the principles of the invention as applied to a parametric oscillator.
DETAILED DESCRIPTION In FIG. I there is shown diagrammatically a distributed feedback laser structure 11 and a suitable pumping means 12. The structure I1 has a periodic spatial variation of period A, which may take one of a number of forms, such as a variation in the index of refraction n of the medium or a variation in the gain constant at. These variations can be expressed by n(z) n n cos Kz i and where z is measured along the optic axis, K 21r/A, and n and 01, are the amplitudes of the spatial modulation of period A. Such a structure, when the active medium is excited above a threshold level by the pump source 12, oscillates in the vicinity of a wavelength A, given by which defines two counter-running waves of complex amplitudes R and S. As shown in the graph of FIG. ll, these waves grow in the presence of gain and feed energy to each other. The boundary conditions for the wave amplitudes are given by where L is the length of the laser structure. In a laser oscillator, at the endpoints a wave starts at zero amplitude and grows to a maximum at the other end. Each pair of periodic variations can be viewed as forming a resonator of length A in which the end surfaces are partially transmitting and partially reflecting. Thus the structure of FIG. I can be viewed as a plurality of partial resonators in tandem.
For large gain factors, that is, where G exp (2aL) I 6 the start oscillation condition, i.e., threshold, is given y 4a /G (rm/M (01 7 If only the refractive index is modulated, as given in equation (I), the threshold condition becomes n (h /L) (lnG/n- G) 8 and where only the gain is modulated, the threshold condition is given by a la 4/ V5 9 The spectral bandwidth of the laser output can be readily determined by linear analysis from the foregoing. Thus, for example, when the gain factor G exceeds the threshold value at center frequency by a factor of 2, the threshold is exceeded over a spectral bandwidth Ah as given by Alt/A, (A /41rnL) lnG 10 In actuality, non-linear effects tend to narrow the bandwidth further. As an example, assume a device of length L 10 mm, G 100, and A 0.63pm (center frequency). From equation (8) it can be seen that oscillation occurs if n 2 l0 and from equation it can be seen that the bandwidth is Ah'-'0.lA. Such a bandwidth is at least an order of magnitude less than that of a conventional dye laser.
FIG. 2 depicts an illustrative embodiment of the invention wherein the laser member comprises a dichromated gelatin film 21 deposited on, for example, a glass substrate 22. Formed within the film 21 are a plurality of interference planes 23 of index of refraction change, spaced a distance A apart. The planes 23 may be produced in the gelatin by interference between two coherent ultraviolet beams from, for example, a I-Ie-Cd laser, after which the gelatin is developed. This is a holographic technique well known to workers in the art, and produces time constant spatially periodic index of refraction changes in the gelatin. The gelatin is impregnated with an active laser medium such as a laser dye, e.g., Rhodamine 6G. Suitable pumping means, such as, for example, the ultraviolet radiation from a nitrogen laser, serves to activate the laser. In such a laser of a length of 10mm and a width of 0.1 mm, with a frine spacing A of 03pm, pumping densities in excess of 10 W/cm produce laser oscillations in the structure at approximately 0.63am with a spatial bandwidth of less than0.5A. A similar laser, without the periodic variations of refractive index of the embodiment of FIG. 2 produces oscillations centered at approximately 0.59pm and having a bandwidth of approximately 50A. Thus it can be seen that the present invention, as embodied in the device of FIG. 2, produces line narrowing by a factor of 100.
In FIG. 3 there is shown still another embodiment of the present invention wherein a solid state laser medium 31 such as, for example, neodymium YAG, has induced therein a substantially time constant, spatially periodic interference pattern produced by the interference between angularly directed pumping lights from first and second coherent pump sources 32 and 33, thereby producing periodic gain variation. The two pump sources shown are intended to be symbolic or numerous arrangements. An expeditious way of achieving the desired frequency and phase relationship of the two beams is through the use of a single pump whose output is split into two beams with a mirror arrangement for directing the beams into the median at the desired angles. Proper choice of pump wavelength and angular direction of the beams produces the desired spacing A. The output of the laser may be utilized in any suitable manner such as, for example, utilization apparatus 34. The arrangement of FIG. 3 has the added virtue of tunability since variations in the angle 0 produce changes in A, thereby changing the laser wavelength.
From equation (3) it can be seen that the wavelength of oscillation A, is a function of the index of refraction n of the medium. Thus, in, for example, the arrangement of FIG. 3, for a fixed A, tuning may also be achieved by varying n, where the nature of the medium permits. For example, in a dye laser where the dye is Rhodamine 6G and the solvent is a mixture of methanol and benzyl alcohol, the index of refraction can easily be varied from 1.33 to 1.55 by varying the proportions of the solvent constituents. In an arrangement such as FIG. 3, for a fixed angle 0 of approximately l07.6, a change of 0.01 in n changes A, by approximately 43A. for a dye concentration of I X 10*M.
Periodic pump variations similar to those of FIG. 3 can also be realized by the arrangement of FIG. 4 wherein the laser medium 41, which may be any of a number of types, has deposited thereon or in proximity thereto an optical grating 42 which produces within the medium periodic intensity variations in the pumping energy from the pump source 43.
In a semiconductor laser, the pump periodicities of FIGS. 3 and 4 can be achieved by the arrangement of FIG. 5. The embodiment of FIG. 5 comprises a semiconductor laser 51 of suitable material deposited or mounted on a substrate 52. On one surface of the member 51 is a current mask 53 which permits pumping or energizing current from a current supply electrode 54 to pass only through apertures 56 which are spaced a distance A apart. The net effect is to produce a periodic gain variation within the semiconductor laser member 51.
The foregoing embodiments of the invention depend upon index of refraction or gain variations to achieve the desired results. It is also possible to produce a laser oscillator in accordance with the principles of the invention through spatially periodic variations of the propagation constant B of the active medium. Such an arrangement is shown in FIG. 6. The device of FIG. 6 comprises a thin film active medium 61 of, for example, neodymium doped high index glass, mounted or deposited upon a suitable substrate 62. A source of pumping energy 63 serves to excite the active medium 6]. Disposed on the surface of the medium 61 are a plurality of dielectric elements 64 of glass, for example, which extend across the member 61 and are parallel to each other. Elements 64 are spaced a distance A apart, and, through the mechanism of dielectric loading, producing variations in the propagations constant B of the thin film member 61, spaced a distance A apart.
In FIG. 7 there is shown an arrangement similar to that of FIG. 6. A thin film member 71 of suitable active material is mounted or deposited upon a suitable substrate 72. A pumping means 73 supplies energy to the medium 711. In accordance with the principles of the invention, one surface of member 71 has a plurality of thickness variations 74 of periodicity A. These varia tions in turn produce variations in the propagation constant B of the medium, of a periodicity A.
In FIG. 8 there is shown an arrangement in which the principles of the invention are utilized in a parametric oscillator. A member 81 of suitable material, such as, for example, lithium niobate, is end pumped by a pumping laser 82, such as, for example, a krypton ion laser, which emits light in the red region of the spectrum. In accordance with the principles of the present invention, there is formed within the member 81 a time constant, spatially periodic index of refraction change by means of the interference between two coherent beams from auxiliary lasers 83 and 84, directed into the medium 81 at an angle 0 to each other. As is the case in the arrangement of FIG. 3, a pair of beam sources is intended to symbolize numerous arrangements. In actuality, a single source with a beam splitter and scissor arrangement is perhaps the most expeditious way of insuring the proper phase and frequency relationships between the two beams. The interference pattern is created in the medium through the well known damage mechanism which occurs in lithium niobate, for example, when subjected to coherent radiation.
For parametric oscillations, the period A of the interference pattern may be such as to feed back the idler wave. Thus the auxiliary laser or lasers 83, 84 may be argon ion lasers, which produce light in the ultraviolet region of the spectrum. On the other hand A may be chosen to feed back the signal frequency, or, in certain cases, it may be such that both signal and idler are fed back.
The various principles and features of the present invention have been illustrated in the foregoing as applied to numerous embodiments. Various other arrangements utilizing these principles and features may occur to workers in the art without departure from the spirit of the invention.
What is claimed is:
T. An optical frequency oscillator comprising an active medium and a feedback mechanism, said feedback mechanism comprising substantially time constant, spatially periodic perturbations in the transmission characteristics of the medium continuously along the length thereof and substantially transverse to the optical direction of propagation of energy in the medium, said perturbations being of sufficient magnitude and being spaced by an integral multiple of one-half wave lengths of the optical frequency oscillations to produce sufficient feedback of the optical energy to sustain oscillations, and means for exciting said active medium to produce oscillations.
2. An optical frequency oscillator as claimed in claim 1 wherein the periodicity of said perturbations is given y h /2n A where A is the period, it, is the wavelength of oscillations and n is the index of refraction of said medium.
3. An optical frequency oscillator as claimed in claim 2 wherein said perturbations are of the form n(z) n n cos Kz where z is distance measured along the optical axis of said oscillator, in is the maximum amplitude of the index of refraction, and K 21r/A.
4. An optical frequency oscillator as claimed in claim 2 wherein said perturbations are of the form 01(1) or 11 cos Kz where at is the gain of the active medium, 2 is distance measured along the optical axis of the oscillator, 0:, is the maximum gain of the medium, and K 21r/A.
5. An optical frequency oscillator comprising an active medium and a feedback mechanism, said feedback mechanism comprising means for producing substantially time constant, spatially periodic perturbations in the gain characteristics of the medium continuously along the length thereof and substantially transverse to the direction of propagation of optical energy in the medium, said perturbations being of sufficient magnitude and being spaced by an integral multiple of onehalf wave lengths of the optical frequency oscillations to produce sufficient feedback of the optical energy to sustain oscillations, and pumping means for exciting said active medium to produce oscillations.
6. An optical frequency oscillator as claimed in claim 5 wherein said means for producing substantially time constant, spatially periodic perturbations comprises means for directing pumping energy into said medium at an angle to the direction of pumping energy of said pumping means.
7. An optical frequency oscillator as claimed in claim 5 wherein said means for producing substantially time constant, spatially periodic perturbations comprises means for causing the pump energy to enter said active medium at spaced intervals along the length thereof.
8. An optical frequency oscillator as claimed in claim 7 wherein said last mentioned means comprises a diffraction grating adjacent to and extending along the length of said active medium.
9. An optical frequency oscillator as claimed in claim 7 wherein said last mentioned means comprises an apertured mask extending along the length of said active medium.
110. An optical frequency oscillator comprising an active medium and a feedback mechanism, said feedback mechanism comprising means for producing substantially time constant, spatially periodic perturbations in the propagation constant of said medium continuously along the length thereof and substantially transverse to the direction of propagation of optical energy in the medium, said perturbations being of sufficient magnitude and being spaced by an integral multiple of onehalf wave lengths of the optical frequency oscillations to produce sufficient feedback of the optical energy to dium.
12. An optical frequency oscillator as claimed in claim 10 wherein said active medium is of solid material and said means for producing substantially time constant, spatially periodic perturbations in the propagation constant comprises a plurality of spaced thickness variations along the length of said medium.
IF =0 i t
Claims (12)
1. An optical frequency oscillator comprising an active medium and a feedback mechanism, said feedback mechanism comprising substantially time constant, spatially periodic perturbations in the transmission characteristics of the medium continuously along the length thereof and substantially transverse to the optical direction of propagation of energy in the medium, said perturbations being of sufficient magnitude and being spaced by an integral multiple of one-half wave lengths of the optical frequency oscillations to produce sufficient feedback of the optical energy to sustain oscillations, and means for exciting said active medium to produce oscillations.
2. An optical frequency oscillator as claimed in claim 1 wherein the periodicity of said perturbations is given by lambda o/2n Lambda where Lambda is the period, lambda o is the wavelength of oscillations and n is the index of refraction of said medium.
3. An optical frequency oscillator as claimed in claim 2 wherein said perturbations are of the form n(z) n + n1 cos Kz where z is distance measured along the optical axis of said oscillator, n1 is the maximum amplitude of the index of refraction, and K 2 pi / Lambda .
4. An optical frequency oscillator as claimed in claim 2 wherein said perturbations are of the form Alpha (z) Alpha + Alpha 1 cos Kz where Alpha is the gain of the active medium, z is distance measured along the optical axis of the oscillator, Alpha 1 is the maximum gain of the medium, and K 2 pi / Lambda .
5. An optical frequency oscillator comprising an active medium and a feedback mechanism, said feedback mechanism comprising means for producing substantially time constant, spatially periodic perturbations in the gain characteristics of the medium continuously along the length thereof and substantially transverse to the direction of propagation of optical energy in the medium, said perturbations being of sufficient magnitude and being spaced by an integral multiple of one-half wave lengths of the optical frequency oscillations to produce sufficient feedback of the optical energy to sustain oscillations, and pumping means for exciting said active medium to produce oscillations.
6. An optical frequency oscillator as claimed in claim 5 wherein said means for producing substantially time constant, spatially periodic perturbations comprises means for directing pumping eNergy into said medium at an angle to the direction of pumping energy of said pumping means.
7. An optical frequency oscillator as claimed in claim 5 wherein said means for producing substantially time constant, spatially periodic perturbations comprises means for causing the pump energy to enter said active medium at spaced intervals along the length thereof.
8. An optical frequency oscillator as claimed in claim 7 wherein said last mentioned means comprises a diffraction grating adjacent to and extending along the length of said active medium.
9. An optical frequency oscillator as claimed in claim 7 wherein said last mentioned means comprises an apertured mask extending along the length of said active medium.
10. An optical frequency oscillator comprising an active medium and a feedback mechanism, said feedback mechanism comprising means for producing substantially time constant, spatially periodic perturbations in the propagation constant of said medium continuously along the length thereof and substantially transverse to the direction of propagation of optical energy in the medium, said perturbations being of sufficient magnitude and being spaced by an integral multiple of one-half wave lengths of the optical frequency oscillations to produce sufficient feedback of the optical energy to sustain oscillations, and pumping means for exciting said active medium to produce oscillations.
11. An optical frequency oscillator as claimed in claim 10 wherein said means for producing substantially time constant, spatially periodic perturbations in the propagation constant comprises a plurality of dielectric members spaced along the length of said active medium for periodically dielectrically loading said medium.
12. An optical frequency oscillator as claimed in claim 10 wherein said active medium is of solid material and said means for producing substantially time constant, spatially periodic perturbations in the propagation constant comprises a plurality of spaced thickness variations along the length of said medium.
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US10065970A | 1970-12-22 | 1970-12-22 | |
US12816571A | 1971-03-25 | 1971-03-25 |
Publications (1)
Publication Number | Publication Date |
---|---|
US3760292A true US3760292A (en) | 1973-09-18 |
Family
ID=26797405
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US00128165A Expired - Lifetime US3760292A (en) | 1970-12-22 | 1971-03-25 | Integrated feedback laser |
Country Status (10)
Country | Link |
---|---|
US (1) | US3760292A (en) |
JP (1) | JPS5336319B1 (en) |
BE (1) | BE776865A (en) |
CA (1) | CA954616A (en) |
DE (1) | DE2163439C3 (en) |
FR (1) | FR2118975B1 (en) |
GB (1) | GB1354928A (en) |
IT (1) | IT943300B (en) |
NL (1) | NL173581C (en) |
SE (1) | SE375411B (en) |
Cited By (32)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3891302A (en) * | 1973-09-28 | 1975-06-24 | Western Electric Co | Method of filtering modes in optical waveguides |
US3937554A (en) * | 1972-09-29 | 1976-02-10 | Hitachi, Ltd. | Holograms impregnated with laser active material |
US3967213A (en) * | 1975-03-05 | 1976-06-29 | California Institute Of Technology | X-ray laser with a single crystal waveguide structure |
US3970360A (en) * | 1974-04-19 | 1976-07-20 | Siemens Aktiengesellschaft | Wave-guide structure with a multi-layer system and methods for producing same |
US3993485A (en) * | 1975-05-27 | 1976-11-23 | Bell Telephone Laboratories, Incorporated | Photopolymerization process and related devices |
DE2703907A1 (en) * | 1976-02-02 | 1977-08-04 | Western Electric Co | REINFORCEMENT DEVICE WITH DISTRIBUTED FEEDBACK |
US4178604A (en) * | 1973-10-05 | 1979-12-11 | Hitachi, Ltd. | Semiconductor laser device |
DE2951000A1 (en) * | 1978-12-28 | 1980-07-17 | Fizitscheskij Inst Akademii Na | Flat or spherical laser construction - mounting laser active material in void for peripheral external excitation |
US4236124A (en) * | 1978-11-03 | 1980-11-25 | The United States Of America As Represented By The United States Department Of Energy | CO2 optically pumped distributed feedback diode laser |
US4400813A (en) * | 1981-07-20 | 1983-08-23 | Bell Telephone Laboratories, Incorporated | Crenelated-ridge waveguide laser |
US4412719A (en) * | 1981-04-10 | 1983-11-01 | Environmental Research Institute Of Michigan | Method and article having predetermined net reflectance characteristics |
US4416013A (en) * | 1981-11-30 | 1983-11-15 | The United States Of America As Represented By The Secretary Of The Navy | Distributed feedback laser employing the stark effect |
US4464762A (en) * | 1982-02-22 | 1984-08-07 | Bell Telephone Laboratories, Incorporated | Monolithically integrated distributed Bragg reflector laser |
US4573163A (en) * | 1982-09-13 | 1986-02-25 | At&T Bell Laboratories | Longitudinal mode stabilized laser |
US4661783A (en) * | 1981-03-18 | 1987-04-28 | The United States Of America As Represented By The Secretary Of The Navy | Free electron and cyclotron resonance distributed feedback lasers and masers |
US4740987A (en) * | 1986-06-30 | 1988-04-26 | American Telephone And Telegraph Company, At&T Bell Laboratories | Distributed-feedback laser having enhanced mode selectivity |
US4905253A (en) * | 1989-01-27 | 1990-02-27 | American Telephone And Telegraph Company | Distributed Bragg reflector laser for frequency modulated communication systems |
US4904045A (en) * | 1988-03-25 | 1990-02-27 | American Telephone And Telegraph Company | Grating coupler with monolithically integrated quantum well index modulator |
US4908833A (en) * | 1989-01-27 | 1990-03-13 | American Telephone And Telegraph Company | Distributed feedback laser for frequency modulated communication systems |
US4914667A (en) * | 1987-01-21 | 1990-04-03 | American Telephone And Telegraph Company, At&T Bell Laboratories | Hybrid laser for optical communications, and transmitter, system, and method |
US5052015A (en) * | 1990-09-13 | 1991-09-24 | At&T Bell Laboratories | Phase shifted distributed feedback laser |
US5140456A (en) * | 1991-04-08 | 1992-08-18 | General Instrument Corporation | Low noise high power optical fiber amplifier |
US5224115A (en) * | 1991-07-17 | 1993-06-29 | The United States Of America As Represented By The Secretary Of The Air Force | Distributed feedback laser implemented using an active lateral grating |
US6246515B1 (en) | 1998-12-18 | 2001-06-12 | Corning Incorporated | Apparatus and method for amplifying an optical signal |
EP1222616A1 (en) * | 1999-02-08 | 2002-07-17 | Spectra Systems Corporation | Optically-based methods and apparatus for sorting, coding, and authentication using a narrowband emission gain medium |
US20050040410A1 (en) * | 2002-02-12 | 2005-02-24 | Nl-Nanosemiconductor Gmbh | Tilted cavity semiconductor optoelectronic device and method of making same |
US20050117623A1 (en) * | 2003-12-01 | 2005-06-02 | Nl-Nanosemiconductor Gmbh | Optoelectronic device incorporating an interference filter |
US20050226294A1 (en) * | 2004-04-07 | 2005-10-13 | Nl-Nanosemiconductor Gmbh | Optoelectronic device based on an antiwaveguiding cavity |
US20050271092A1 (en) * | 2004-06-07 | 2005-12-08 | Nl-Nanosemiconductor Gmbh | Electrooptically wavelength-tunable resonant cavity optoelectronic device for high-speed data transfer |
US20050276296A1 (en) * | 2002-02-12 | 2005-12-15 | Nikolai Ledentsov | Tilted cavity semiconductor device and method of making same |
US20120155888A1 (en) * | 2010-12-17 | 2012-06-21 | Ho-Chul Ji | Optical modulator with reduced size and optical transmitter including the same |
CN110622058A (en) * | 2017-05-26 | 2019-12-27 | 微软技术许可有限责任公司 | Optical waveguide with coherent light source |
Families Citing this family (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS58181000A (en) * | 1982-04-19 | 1983-10-22 | 株式会社日立製作所 | Same phase light super radiation emission device |
US4543533A (en) * | 1982-09-01 | 1985-09-24 | Clarion Co., Ltd. | Parametric amplifier |
Citations (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3239688A (en) * | 1962-12-31 | 1966-03-08 | Ibm | Logical devices |
US3448405A (en) * | 1966-02-17 | 1969-06-03 | Bell Telephone Labor Inc | Scanning laser |
US3451010A (en) * | 1967-03-10 | 1969-06-17 | Hughes Aircraft Co | Laser systems employing a solid laser material |
US3579142A (en) * | 1969-07-18 | 1971-05-18 | Us Navy | Thin film laser |
US3611190A (en) * | 1969-10-16 | 1971-10-05 | American Optical Corp | Laser structure with a segmented laser rod |
Family Cites Families (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3222615A (en) * | 1961-10-10 | 1965-12-07 | Ibm | Cylindrical lasers utilizing internal reflection techniques |
DE1281066B (en) * | 1964-08-17 | 1968-10-24 | Siemens Ag | Quantum mechanical transmitter or amplifier of the highest spectral purity |
US3390278A (en) * | 1966-04-12 | 1968-06-25 | Bell Telephone Labor Inc | Optical liquid parametric devices with increased coherence length using dye |
-
1971
- 1971-03-25 US US00128165A patent/US3760292A/en not_active Expired - Lifetime
- 1971-10-22 CA CA125,860A patent/CA954616A/en not_active Expired
- 1971-12-14 SE SE7116003A patent/SE375411B/xx unknown
- 1971-12-17 BE BE776865A patent/BE776865A/en not_active IP Right Cessation
- 1971-12-17 GB GB5860371A patent/GB1354928A/en not_active Expired
- 1971-12-17 IT IT71147/71A patent/IT943300B/en active
- 1971-12-21 NL NLAANVRAGE7117576,A patent/NL173581C/en not_active IP Right Cessation
- 1971-12-21 FR FR7145895A patent/FR2118975B1/fr not_active Expired
- 1971-12-21 DE DE2163439A patent/DE2163439C3/en not_active Expired
- 1971-12-22 JP JP10375371A patent/JPS5336319B1/ja active Pending
Patent Citations (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3239688A (en) * | 1962-12-31 | 1966-03-08 | Ibm | Logical devices |
US3448405A (en) * | 1966-02-17 | 1969-06-03 | Bell Telephone Labor Inc | Scanning laser |
US3451010A (en) * | 1967-03-10 | 1969-06-17 | Hughes Aircraft Co | Laser systems employing a solid laser material |
US3579142A (en) * | 1969-07-18 | 1971-05-18 | Us Navy | Thin film laser |
US3611190A (en) * | 1969-10-16 | 1971-10-05 | American Optical Corp | Laser structure with a segmented laser rod |
Non-Patent Citations (1)
Title |
---|
Miller: Integrated Optics: An Introduction , The Bell System Technical Journal, Vol. 48, pp. 2059 2069, Sept. 1969. * |
Cited By (45)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3937554A (en) * | 1972-09-29 | 1976-02-10 | Hitachi, Ltd. | Holograms impregnated with laser active material |
US3891302A (en) * | 1973-09-28 | 1975-06-24 | Western Electric Co | Method of filtering modes in optical waveguides |
US4178604A (en) * | 1973-10-05 | 1979-12-11 | Hitachi, Ltd. | Semiconductor laser device |
US3970360A (en) * | 1974-04-19 | 1976-07-20 | Siemens Aktiengesellschaft | Wave-guide structure with a multi-layer system and methods for producing same |
US3967213A (en) * | 1975-03-05 | 1976-06-29 | California Institute Of Technology | X-ray laser with a single crystal waveguide structure |
US3993485A (en) * | 1975-05-27 | 1976-11-23 | Bell Telephone Laboratories, Incorporated | Photopolymerization process and related devices |
DE2703907A1 (en) * | 1976-02-02 | 1977-08-04 | Western Electric Co | REINFORCEMENT DEVICE WITH DISTRIBUTED FEEDBACK |
US4096446A (en) * | 1976-02-02 | 1978-06-20 | Bell Telephone Laboratories, Incorporated | Distributed feedback devices with perturbations deviating from uniformity for removing mode degeneracy |
US4236124A (en) * | 1978-11-03 | 1980-11-25 | The United States Of America As Represented By The United States Department Of Energy | CO2 optically pumped distributed feedback diode laser |
DE2951000A1 (en) * | 1978-12-28 | 1980-07-17 | Fizitscheskij Inst Akademii Na | Flat or spherical laser construction - mounting laser active material in void for peripheral external excitation |
US4661783A (en) * | 1981-03-18 | 1987-04-28 | The United States Of America As Represented By The Secretary Of The Navy | Free electron and cyclotron resonance distributed feedback lasers and masers |
US4412719A (en) * | 1981-04-10 | 1983-11-01 | Environmental Research Institute Of Michigan | Method and article having predetermined net reflectance characteristics |
US4400813A (en) * | 1981-07-20 | 1983-08-23 | Bell Telephone Laboratories, Incorporated | Crenelated-ridge waveguide laser |
US4416013A (en) * | 1981-11-30 | 1983-11-15 | The United States Of America As Represented By The Secretary Of The Navy | Distributed feedback laser employing the stark effect |
US4464762A (en) * | 1982-02-22 | 1984-08-07 | Bell Telephone Laboratories, Incorporated | Monolithically integrated distributed Bragg reflector laser |
US4573163A (en) * | 1982-09-13 | 1986-02-25 | At&T Bell Laboratories | Longitudinal mode stabilized laser |
US4740987A (en) * | 1986-06-30 | 1988-04-26 | American Telephone And Telegraph Company, At&T Bell Laboratories | Distributed-feedback laser having enhanced mode selectivity |
US4914667A (en) * | 1987-01-21 | 1990-04-03 | American Telephone And Telegraph Company, At&T Bell Laboratories | Hybrid laser for optical communications, and transmitter, system, and method |
US4904045A (en) * | 1988-03-25 | 1990-02-27 | American Telephone And Telegraph Company | Grating coupler with monolithically integrated quantum well index modulator |
US4905253A (en) * | 1989-01-27 | 1990-02-27 | American Telephone And Telegraph Company | Distributed Bragg reflector laser for frequency modulated communication systems |
US4908833A (en) * | 1989-01-27 | 1990-03-13 | American Telephone And Telegraph Company | Distributed feedback laser for frequency modulated communication systems |
US5052015A (en) * | 1990-09-13 | 1991-09-24 | At&T Bell Laboratories | Phase shifted distributed feedback laser |
US5140456A (en) * | 1991-04-08 | 1992-08-18 | General Instrument Corporation | Low noise high power optical fiber amplifier |
US5224115A (en) * | 1991-07-17 | 1993-06-29 | The United States Of America As Represented By The Secretary Of The Air Force | Distributed feedback laser implemented using an active lateral grating |
US6246515B1 (en) | 1998-12-18 | 2001-06-12 | Corning Incorporated | Apparatus and method for amplifying an optical signal |
EP1222616A4 (en) * | 1999-02-08 | 2005-07-06 | Spectra Systems Corp | Optically-based methods and apparatus for sorting, coding, and authentication using a narrowband emission gain medium |
US6552290B1 (en) * | 1999-02-08 | 2003-04-22 | Spectra Systems Corporation | Optically-based methods and apparatus for performing sorting coding and authentication using a gain medium that provides a narrowband emission |
US20030108074A1 (en) * | 1999-02-08 | 2003-06-12 | Spectra Science Corporation | Optically-based methods and apparatus for performing sorting, coding and authentication using a gain medium that provides a narrowband emission |
AU770214B2 (en) * | 1999-02-08 | 2004-02-19 | Spectra Systems Corporation | Optically-based methods and apparatus for sorting, coding, and authentication using a narrowband emission gain medium |
US6832783B2 (en) | 1999-02-08 | 2004-12-21 | Spectra Science Corporation | Optically-based methods and apparatus for performing sorting, coding and authentication using a gain medium that provides a narrowband emission |
EP1222616A1 (en) * | 1999-02-08 | 2002-07-17 | Spectra Systems Corporation | Optically-based methods and apparatus for sorting, coding, and authentication using a narrowband emission gain medium |
JP2002536214A (en) * | 1999-02-08 | 2002-10-29 | スペクトラ システムズ コーポレーション | Light-based method and apparatus for sorting, encoding, and authenticating using a narrowband emission gain medium |
JP2010267285A (en) * | 1999-02-08 | 2010-11-25 | Spectra Systems Corp | Optically-based method and apparatus for performing sorting, coding and authentication using gain medium providing narrowband emission |
US7031360B2 (en) | 2002-02-12 | 2006-04-18 | Nl Nanosemiconductor Gmbh | Tilted cavity semiconductor laser (TCSL) and method of making same |
US20050040410A1 (en) * | 2002-02-12 | 2005-02-24 | Nl-Nanosemiconductor Gmbh | Tilted cavity semiconductor optoelectronic device and method of making same |
US20050276296A1 (en) * | 2002-02-12 | 2005-12-15 | Nikolai Ledentsov | Tilted cavity semiconductor device and method of making same |
US20050117623A1 (en) * | 2003-12-01 | 2005-06-02 | Nl-Nanosemiconductor Gmbh | Optoelectronic device incorporating an interference filter |
US20050226294A1 (en) * | 2004-04-07 | 2005-10-13 | Nl-Nanosemiconductor Gmbh | Optoelectronic device based on an antiwaveguiding cavity |
US7339965B2 (en) | 2004-04-07 | 2008-03-04 | Innolume Gmbh | Optoelectronic device based on an antiwaveguiding cavity |
US7369583B2 (en) | 2004-06-07 | 2008-05-06 | Innolume Gmbh | Electrooptically wavelength-tunable resonant cavity optoelectronic device for high-speed data transfer |
US20050271092A1 (en) * | 2004-06-07 | 2005-12-08 | Nl-Nanosemiconductor Gmbh | Electrooptically wavelength-tunable resonant cavity optoelectronic device for high-speed data transfer |
US20120155888A1 (en) * | 2010-12-17 | 2012-06-21 | Ho-Chul Ji | Optical modulator with reduced size and optical transmitter including the same |
US8818203B2 (en) * | 2010-12-17 | 2014-08-26 | Samsung Electronics Co., Ltd. | Optical modulator with reduced size and optical transmitter including the same |
CN110622058A (en) * | 2017-05-26 | 2019-12-27 | 微软技术许可有限责任公司 | Optical waveguide with coherent light source |
CN110622058B (en) * | 2017-05-26 | 2022-05-06 | 微软技术许可有限责任公司 | Optical waveguide with coherent light source |
Also Published As
Publication number | Publication date |
---|---|
JPS5336319B1 (en) | 1978-10-02 |
DE2163439B2 (en) | 1980-12-11 |
FR2118975A1 (en) | 1972-08-04 |
BE776865A (en) | 1972-04-17 |
GB1354928A (en) | 1974-06-05 |
DE2163439C3 (en) | 1981-07-23 |
NL173581C (en) | 1984-02-01 |
IT943300B (en) | 1973-04-02 |
FR2118975B1 (en) | 1974-06-07 |
DE2163439A1 (en) | 1972-07-13 |
NL7117576A (en) | 1972-06-26 |
SE375411B (en) | 1975-04-14 |
CA954616A (en) | 1974-09-10 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
US3760292A (en) | Integrated feedback laser | |
US4287486A (en) | Laser resonator cavities with wavelength tuning arrangements | |
US3898585A (en) | Leaky corrugated optical waveguide device | |
Kogelnik et al. | Stimulated emission in a periodic structure | |
White et al. | Coherent oscillation by self‐induced gratings in the photorefractive crystal BaTiO3 | |
US3868589A (en) | Thin film devices and lasers | |
US6832024B2 (en) | Method and apparatus for fiber bragg grating production | |
US4918704A (en) | Q-switched solid state pulsed laser with injection seeding and a gaussian output coupling mirror | |
US3136959A (en) | culver | |
US3579130A (en) | Thin film active interference filter | |
US3611436A (en) | Mode-selective laser using resonant prisms | |
US3747021A (en) | Wide range continuously tunable thin film laser | |
US4233569A (en) | High power laser with tuning and line narrowing capability | |
JPS6290618A (en) | Light modulator | |
US3504299A (en) | Optical maser mode selector | |
US4048516A (en) | Laser apparatus for producing stimulated Raman scattering | |
US3703687A (en) | Intracavity modulator | |
US5754572A (en) | Mirrorless, distributed-feedback, ultraviolet, tunable, narrow-linewidth, solid state laser | |
US3309621A (en) | Mode controlled laser | |
US3902137A (en) | Electro-optic diffraction grating tuned laser | |
CA1071745A (en) | Laser resonator cavities with wavelength tuning arrangements | |
Hill et al. | A distributed-feedback side-coupled laser | |
EP0805530B1 (en) | Wavelength tunable laser | |
EP0556016B1 (en) | Wavelength variable laser device | |
US3478277A (en) | Optical mode selector |